Think I'd still go with the Vengeance RAM tbh but mainly because I think the TeamGroup RAM is arse ugly (I'm being a tart I know
)!
With regards to radiators, the beauty of the 800D and other 'shelved' cases is the option of putting rads under the shelf. Have a look at
this, a bit more extreme than what you're planning with the watercooling but rad wise this is probably what you should be doing imo. You could get away with going 2x240 but for an extra tenner or so I'd go 360 +240. (You can also lay the bottom rad flat like
so).
Pump wise, as I say I'd recommend a D5. You can get them in the
same housing as the pump you'd specced or set one up on it's own like I have done in my build (see my sig) which gives you more freedom to use a stand alone res.
Be aware that the res you've chosen doesn't include the pump.
You may notice in my build that I have a 240 rad and another single, the single is a 140 which is in between a 120 and 240. Overall adds to a bit over a 360 rad but I will be replacing my 240 with a 360 as soon as I can a) afford it and b) be bothered to mod my case to take a 360 up top!
EDIT:
Fluid wise, get yourself to your local garage and buy some distilled water for about £1 and add a few drops of
this (< that bottle will last a LONG time).
Another thought. What made you choose the KFA 670s? I'm not 100% on this but they don't look like reference cards to me which will likely mean the full cover blocks won't fit.
EDIT II:
Thinking about it again I'm 99% sure those cards won't take the full cover waterblocks as they're the 4GB cards. Go for reference cards mate, they'll only be 2GB but in SLI this'll make naff all difference really, you'll see more benefit with upping the clock speeds which is where the fun begins.